Dynamic analysis of a heavy duty marine gearbox with gear mesh coupling

Abstract

A three-dimensional finite-element model of a coupled gear—rotor—bearing—housing system is developed by combining the gearbox transmission model with the housing structure model of a heavy duty marine gearbox. The numerical simulation of the dynamic characteristics is performed to analyse the effects of both internal gear meshing and external shaft-related dynamic excitations on the gearbox transmission response. The natural modes, vibration response, and generated noise levels are computed in the simulation process. These results are employed to gain insights into the primary controlling parameters, to forecast the severity of the dynamic response, and to assess the acceptability of the gearbox design. In fact, the proposed modelling approach not only provides a more comprehensive understanding of the heavy duty marine gearbox system, but can also serve as the basis for gear dynamic optimization. To demonstrate the salient features of the proposed simulation model, a specific marine gearbox example is studied in detail. Finally, a vibration experimental study was performed on the marine gearbox system. The vibrations at some locations concerned were monitored and analysed. The experimental vibration and structure noise results compared well with the analytical prediction.